A bone-headed Brooklynite who tried — and failed — to hire a hit man to take out his estranged wife was singing the jailhouse blues Monday when he was sentenced to two to six years in prison.

Gathering in Manhattan Criminal Court, Rockefeller Auguste told a judge that he was “deeply remorseful” for plotting to kill his wife just so he could get the wedding ring he bought for her back.

This plan, failed from the outset, prosecutors said.

In his search to find a reliable hit man, Auguste ended up confiding in an undercover cop posing as a paid assassin back in August 2008.

Auguste dug a deeper hole when, during follow up conversations with his hit man, he gave the undercover cop a samurai sword, a $500 down payment. He also asked the cop to kill his wife, then chop off her hand sporting the $27,000 wedding ring he bought for her back when things were better between them.

In the end, not a hair on the woman’s head was harmed. Auguste was taken into custody on conspiracy and other charges. He pleaded guilty last month, prosecutors said.

Harold Levy, Auguste’s defense attorney, told reporters that his client was “emotionally overcome” by financial problems, as well as affairs of the heart when his relationship went south and she filed for divorce.

Feds on defense in

St. Guillen suit

Members of the U.S. Probation and Pre-Trial Services could be named as defendants in a civil suit filed by the family of Immette St. Guillen, a federal judge ruled.

In her findings released last week Federal Judge Dora Irizarry said that the U.S. Probation department had “improperly supervised” the man who had kidnapped and killed St. Guillen and that there was evidence that they “botched the case.”

Attorneys for St. Guillen’s family said that Darryl Littlejohn, the man convicted of killing the pretty grad student, had been released from prison back in 2004 for a bank robbery conviction and put on supervised release.

From there, Littlejohn managed to slip through the cracks, attorneys for St. Guillen’s family said, adding that U.S. Probation and pre-trial services should have known that he was working at a bouncer at a Manhattan nightclub — which was a direct violation of his parole.

During his recent trial, Brooklyn prosecutors proved that Littlejohn had grabbed St. Guillen from the club, back in February, 2006 and took her to his home where he killed her.

Her battered, naked body was recovered on the side of the Belt Parkway near the Gateway Center a few days later.

Littlejohn was ultimately convicted and sentenced to life in prison.

In her decision, Irizarry did not mince words about the Department of Probation’s inaction in this case.

Members of the U.S. Attorney’s Office Eastern Division, who are representing the U.S. Department of probation in this case, said that they were reviewing Irizarry’s decision and “going over their options,” according to published reports.